1st Edition

Advanced Router Architectures

By Axel K. Kloth Copyright 2006
    240 Pages 73 B/W Illustrations
    by CRC Press

    Routers, switches, and transmission equipment form the backbone of the Internet, yet many users and service technicians do not understand how these nodes really work.

    Advanced Router Architectures addresses how components of advanced routers work together and how they are integrated with each other. This book provides the background behind why these building blocks perform certain functions, and how the function is implemented in general use. It offers an introduction to the subject matter that is intended to trigger deeper interest from the reader. The book explains, for example, why traffic management may be important in certain applications, what the traffic manager does, and how it connects to the rest of the router. The author also examines the implications of the introduction or omission of a traffic manager into an advanced router. The text offers a similar analysis for other router topics such as QOS and policy enforcement, security processing (including DoS/DDoS), and more.

    This book covers which mandatory and which optional building blocks can be found in an advanced router, and how these building blocks operate in conjunction to ensure that the Internet performs as expected.

    Introduction

    Internet Topology Change
    Overview
    Current Status
    Traffic and Traffic Growth

    The Carrier Business Model
    Overview
    Service Level Agreements (SLAs)
    The VoIP Business Model
    Internal Corporate Accounting

    Advanced Routers in Central Office Applications
    Overview
    Central Office (CO) Colocation

    Function Split
    Overview
    Traditional System Partitioning and Function Split
    Functions within the Port Card
    Functions within the Processor Card
    Functions within the Switch Card
    Functions within the OAM&P Card

    High Availability
    Overview
    Definition
    Implications
    Network View of Redundancy and Failsafe Operation
    Example
    Design Life Time and Single Point of Failure Impact
    Definition of Availability
    1+1 Redundancy
    1:1 Redundancy
    2 out of 3 (or N out of N+1) Redundancy
    Redundant Switch Fabric Cards
    Redundant Line Cards
    Redundant Links
    Redundant Power Supplies
    Software Robustness
    OAM&P Control over Redundant Subsystems
    Timed Switchover
    Switchover on Demand
    Reducing Human Error Probability

    The Chassis
    Overview
    Single-board versus Modular Designs

    Line Cards
    Overview
    Definitions
    Functional Requirements
    Further Impact of Advanced Router Architectures
    Differentiation of Functions
    Line Card Implementation in Single-board Designs
    Line Card Implementation in Midplane Designs
    Line Card Implementation in Backplane Designs
    Line Card Messaging and Communications
    Interior and Exterior Border Gateway Protocols
    Line Card Functions for PSTN Internetworking
    Port Card Functions
    Network Processor and Traffic Manager Software Implications Local Control Processors for Line or Processor Cards

    Switch Fabric Cards
    Overview
    Functional Requirements for an Advanced Router's Core
    History of Router-internal Interconnects
    Basics
    Crosspoint Switches and Crossbar Switches
    Shared Memory Switches
    Non-buffered, Non-queued Switch Fabrics
    Buffered and Queued Switch Fabrics
    Combined Virtually Output Queued Switch Fabrics
    Metrics of Switch Fabrics
    Net Bit Rate or Link Rate Utilization (Minimum, Maximum, Average)
    Throughput (Total and on a per-Link Basis)
    System Availability (Minimum)
    System Uptime (Minimum)
    Reliability (Error Rate)
    Logical Connection Setup Time (Minimum, Maximum, Average)
    Logical Connection Teardown Time (Minimum, Maximum, Average)
    Delay and Latency
    Round-Trip Delay (Minimum, Maximum, Average)
    Cell Delay Variation (CDV) (Minimum, Maximum, Average)
    Scalability
    Field Upgradability
    Resource Utilization on the Network Processor
    Cost Structure
    Feasibility
    Performance Extension
    Alternative Solutions
    The "Switchless Switch"
    Multicast and Broadcast
    Bandwidth Overprovisioning
    Traffic Manager Functions versus Queue Manager Functions
    Deterministic Behavior
    Switch Fabric I/O
    Software Function Set in Local Switch Fabric Control

    Operation, Administration, Maintenance and Provisioning
    Overview
    Definition of OAMP
    Functions of the OAM&P Entity
    Operational Statuses
    Status Transitions
    Relationship with NMC
    Implementation
    Fail-safe and Fault-tolerant OAM&P Entity Operation
    OAM&P Entity Internal Communication
    Examples of Failure Modes of Managed Entities
    The Necessity for the Device-Global View
    Sample OAM&P Card Schematic .

    Biography

    Kloth, Axel K.